that IS a solution, but it requires another piece of hardware. I believe there must be a solution that could provide the same via virtual network driver(like VirtualBox).
There are also external DNS providers that provide blacklisting similar to PI Hole. (Although then you are trusting the DNS provider not to track you.)
Try QubesOS and pihole together:
- https://blog.tufarolo.eu/how-to-configure-pihole-in-qubesos-...
It should let you do exactly that: local pihole to monitor and block traffic from all VMs.
(I haven't tried it. I went the route of a separate pihole enabled network behind my cable modem as I have other devices I'd like to block traffic on too.)